Method and apparatus for treating roofing-grit



A. B. COOKE.

METHOD AND APPARATUS FOR TREATiNG ROOFING GRIT. APPLICATICN FILED AUG-18.19i9.

1,337,822, Patnted'Apr. 20, 1920.

:fiufernor 4 Arm...- ,3. 000,49 .a fldwv iw UNITED STATES PATENT OFFICE.

ARTHUR B. COOKE, OF CHICAGO, ILLINOIS, ASSIGNOR TO STASO LAMINATED SLATE COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF MASSACHUSETTS.

Specification of Letters Patent.

Patented Apr. 20, 1920.

Application filed August 18, 1919. Serial No. 318.184.

To all whom it may concern Be it known that I ARTHUR B. Coonn, a citizen of the United States, and resident of Chicago, county of Cook, and State of Illinois, have invented certain new and useful Improvements in Methods and Apparatus for Treating Roofing-Grit, of which the following is a specification, and which are illustrated in the accompanying drawings,

forming a part thereof.

The invention relates to the preparation of grit for use as a surfacing material upon prepared roofing and the like. Owing to the fact that roofing grit is applied upon 5 the tacky surface of the asphalt coating layer of prepared roofing,.to which it must firmly adhere and for which it must provide a substantially complete covering layer, it is important that the grit should be free 0 from dust, but that it should contain a proportion of smaller particles for filling the openings or voids which would otherwise remain between the particles of larger size. The presence of dust is objectionable for the reason that it covers the tacky surface of the asphalt layer and prevents the adhesion of the grit particles thereto while the pres- Y ence of some small particles is frequently desirable and the amount and size of these for securing the best results may vary with different its. Furthermore, as the production 0 dust andsmaller particles may result from the abrasion of the particles 'upon each other during transportation and 5 handling of the material it is also desirable 7 that the final se aration of dust and small particles should e made at the place where the grit is to be used and'preferably immediately prior to the application of the grit 40 upon the prepared roo g.

The invention accordingly contemplates a method and apparatus for the treatment of roofing grit designed to effect a substantially complete removal ofdust and in addition thereto, the removal of a regulated amount of the smaller grit articles, when desired. The object ofthe invention is to provide a method and apparatus for this purpose which may be used at small expense and without the installation of elaborate equipment but which will effectively accomplish the end desired without any objectionable discharge of dust within the buildings where the use occurs.

In the accompanying drawings;

Figure 1 is a central longitudinal sectional view showing one form of apparatus provided by the invention, and

Fig. 2 is an end View of the same, partly in section.

In carrying out the improved method, the material to be treated is violently agitated to not only separate the grit particles but also to release dust which clings to the surface of the particles and the material is immediately thereafter permitted to fall in a shower through an air blast of regulated intensity. As shown, the treatment is carried out ina housing. as 10, of a flattened rectangular shape except for its sloping bot tom 11, which terminates near one end of the housing in a hopper shaped portion 12 formed by the sloping bottom 11 and sloping portions 31, 32 of the side walls 33, 34. The hopper 12 leads to an outlet conduit 13 through which all loose material falling to the bottom of the housing passes to the place of storage or use. I

Material to be treated is fed into the housing preferably through a vertical inlet conduit 14, which enters the housing 10 at the top of the same adjacent the remote end of the housing from the outlet conduit 13. As a means for separating the particles and to assist in releasing the dust from the surface of the particles, a rapidly revolving wheel 15 having radial blades 16 is placed at a little distance below the opening of the inlet conduit 14, in the path of the entering material. If desired the wheel 15may be conveniently constructed by utilizing an ordinary wooden split pulley to which the blades 16 and rings forming end flanges 17 are secured.

As the wheel 15 desirably turns in the direction indicated by the arrow on Fig. 1, the material is forcibly thrown by the blades 16 against the top of the housing from which it is deflected as shown b the dotted lines. Interference. between tiie particles will modify the result but it will still be true that a large part of the material will be thrown against the top of the housing and fall in a fairly well distributed shower through the housin To draw air rapidly from the casing and to consequently remove the loose dust and some of the finer particles, there is provided a blower, as 35, in this instance serving as an exhaust fan. The exhaust fan is connected with the housing by means of a conduit 18 which leads out of the top of the housing directly over the. outlet conduit 13. The mechanism may be driven by a motor, as 19, driving shaft- 20, u on which wheel 15 is mounted, by means 0 belt 21 and pulley 22. Shaft 20 is journaled in the-side walls of the housing and also carries a pulley 23 which, through belt 24, may drive the exhaust fan 35. Forregulation'of the power of suction a damper 25 is provided in conduit 18. 7

Air is admitted to the. housing through intake pipes, shown as three in number, as 26, 27 and 28, all of less size than. the exhaust pipe 18 and each of which is preferably provided with a separate damper, as 29-, 30- and 36. When the said three inlet pipes are used they may be located, one, as 26,. at the end of the housing 10 remote from the exhaust pipe 18, and the other two. as

27, 28, low down upon the side walls 33,34.

This location of the inlet pipes is designed to provide, an even flow of air upward through the casing to remove the dust and finer particles uniformly from the shower of falling material. By manipulation of dampers 29, 30 and 36, the travel of the air may be adjusted for most efficient action in removing the dust and the proportion of finer material desired.

I claim as my invention 1. In a device ofthe kind described,.in combination, a closed housing having a sloping bottom and a material outlet at the lower end of the-slope, a material inlet in the top, of the housing above the u per end of the slope, means in the path of tlie incoming material to throw the material against the top of the housing whereby it is separated into an open shower and means to exhaust air and dust from the housin 2. In a device of the kin described, in combination, a closed housing, means to feed material to be cleaned into the housing at one end of the upper portion, a material outlet at the other end of the bottom of the housing, an air inlet at the lower portion of the end of the housing below the material inlet, suction means connected to the housing in its top opposite the material inlet, and means to throw the material against the top of the housing whereby it is separated into an openshower.

3. In a device of the kind described, in combination, a housin a material inlet at one end of the top of t e housing, a suction device connected to the other end of the top of the housing, a revoluble agitator below the inlet adapted to throw material against the top of the housing, and a plurality of air inlets in the intermediate portion of the housing.

4.111 a device of the kind described, in combination, a housing, a material inlet at one end of the top of the housing, a suction device connected to the other end of the top of the housing, a revoluble agitator below the inlet adapted to throw material a ainst the to of the housing, a plurality 0' air inlets 1n the lower portion of the housing, a hopper bottom for the housing,

'and a material outlet leading from said hopper. 1

5. The method of removin dust from consists in violently agitating a falling stream of the material to separate it into an open shower and passing an air blast through the said shower.

ARTHUR B; COOKE. 

